The Supreme Court ruled against the federal government's use of a chemical weapons treaty to prosecute a jilted wife. / David Goldman, AP

by Richard Wolf, USA TODAY

by Richard Wolf, USA TODAY

WASHINGTON - The Supreme Court ruled unanimously Monday that the federal government had no business using an international chemical weapons treaty to prosecute a jilted wife seeking revenge on her husband's lover.

In an opinion dripping with sarcasm, the justices belittled the Justice Department's contention that what they called Carol Anne Bond's "two-bit local assault" - a clumsy use of a chemical compound - could have anything in common with war crimes and international terrorism.

"The global need to prevent chemical warfare does not require the federal government to reach into the kitchen cupboard, or to treat a local assault with a chemical irritant as the deployment of a chemical weapon," Chief Justice John Roberts said.

While the decision slapped the Obama administration for excessive prosecutorial zeal, it stopped short of what conservatives sought: a ruling that Congress' implementation of the chemical weapons treaty was unconstitutional. That would have represented a far greater restraint on federal powers.

Instead, six justices said simply that international treaties cannot always supplant local police powers. They noted that Bond's attacks on a woman impregnated by her husband resulted in nothing more serious than a burned thumb treated with water - not the sort of injury such treaties are intended to address.

Allowing Bond to be prosecuted under a treaty aimed at compounds such as ricin, sarin and mustard gas, Roberts said, would elevate dish detergent, stain remover and vinegar to chemical weapons status.

"Any parent would be guilty of a serious federal offense - possession of a chemical weapon - when, exasperated by the children's repeated failure to clean the goldfish tank, he considers poisoning the fish with a few drops of vinegar," he said.

The case of Bond v. United States involved a lurid affair, an act of vengeance, weapons in the same category as those favored by tyrants and terrorists and video surveillance by an ever-vigilant government - all in a peaceful Philadelphia suburb.

Upon discovering that her husband was the father of her best friend's child, Bond, 42, repeatedly spread a combination of potassium dichromate purchased from Amazon.com and 10-chloro-10-H-phenoxarsine taken from her employer on Myrlinda Haynes' car door, mailbox and doorknob.

After sustaining a minor burn on her thumb, Haynes called police, who advised her to take her car to the car wash. When the same compound appeared on her mailbox, she called the post office, putting the case before federal authorities. They installed surveillance cameras and caught Bond in the act, leading to her arrest, conviction and six-year prison term.

Federal district and appeals courts refused to let her off the hook. It took the justices nearly seven months to release their ruling, most likely because three of them -- Antonin Scalia, Clarence Thomas and Samuel Alito -- wanted to go further and rule that the entire law used to prosecute Bond was unconstitutional. All three wrote separate opinions concurring in the result, but not Roberts' reasoning.

By parsing the types of criminal conduct that can and cannot be prosecuted under the law implementing the treaty, Scalia said, a statute "which before was merely broad, is now broad and unintelligible."

In that sense, the decision was a disappointment to conservative groups that had been rooting for the court to overturn its 94-year-old precedent in Missouri v. Holland, which cleared the way for Congress to use federal treaties to supersede states' authority.

"In deciding the case so narrowly ... the court's majority abdicated its duty to check the other branches of government," said Ilya Shapiro of the libertarian Cato Institute. He criticized Roberts, whose decision in 2012 upheld President Obama's health care law, for going "out of his way to avoid hard calls whenever possible."

During oral arguments last November, several justices wondered whether Congress' implementation of the Chemical Weapons Convention of 1997 was intended to encompass crimes that Bond's attorney, former U.S. solicitor general Paul Clement, called "garden-variety assaults."

Solicitor General Donald Verrilli had a hard time convincing the justices when the case was heard. "This is serious business," he implored them, warning that any diminution of the federal government's treaty power could harm U.S. interests on issues ranging from chemical weapons to nuclear non-proliferation.

"There needs to be a comprehensive ban," Verrilli said. "You can't be drawing these kinds of lines."

"Judges are here to draw lines," said Justice Stephen Breyer, a liberal justice clearly bothered by the government's case. "It's better to draw a few lines."